Histological Observation of Helmet Development in the Treehopper Poppea capricornis (Insecta: Hemiptera: Membracidae)

The treehoppers (Hemiptera, Membracidae) are known for possessing a large three-dimensional structure called a helmet. Although some ecological functions of the helmet have already been elucidated, the developmental mechanisms underlying the complex and diverse morphology of the helmet are still largely unknown. The process of helmet formation was first described in Antianthe expansa, which possesses a simple roof-shaped helmet. However, the developmental process in species with more complex helmet morphologies remains largely unexplored. Hence, in this study, we used Poppea capricornis, which possesses a more complex helmet structure than A. expansa, to investigate the helmet development using paraffin sections, micro-CT, and scanning electronic microscopy. Our focus was on the overall helmet developmental process common to both species and formation of structures unique to Poppea and its comparison to Antianthe. As a result, we discovered that miniature structures were also formed in Poppea, similar to Antianthe, during the helmet formation. Common structures that were shared between the two species were discernible at this stage. Additionally, we observed that suprahumeral horns and posterior horns, two morphological traits specific to the Poppea helmet that are apparently similar anatomically, are formed through two distinctly different developmental mechanisms. The suprahumeral horns appeared to be formed by utilizing the nymphal suprahumeral bud as a mold, while we could not detect any nymphal structures potentially used for a mold in the posterior horns formation. Our findings suggest that the helmet formation mechanisms of Antianthe and Poppea employ a common mechanism but form species-specific structures by multiple mechanisms.

Effect of the Infusion of OKY-046, a Thromboxane A2 Synthase Inhibitor, on Urinary Metabolites of Prostacyclin and Thromboxane A2 in Healthy Human Subjects

The influence of OKY-046, a selective thromboxane synthase inhibitor, on prostanoid formation in healthy human subjects was studied. Vehicle (5% glucose solution) or OKY-046 in 5% glucose solution at 15 μg kg−1 min−1 was intravenously administered to five male healthy volunteers for 6 h. Platelet aggregation and thromboxane B2 (TXB2) formation induced by collagen and arachidonic acid were suppressed by the infusion of OKY-046, while both were not affected by the infusion of vehicle. Urinary excretion of 11-dehydro-thromboxane B2, one of major urinary metabolites of thromboxane A2 (TXA2) was decreased by the infusion of OKY-046, while that of 2,3-dinor-6-keto-prostaglandin F1α, one of major urinary metabolites of prostacyclin (PGI2) was increased. The present study demonstrated that the infusion of OKY-046 improved the balance of TXA2/PGI2 into antithrombotic state in healthy subjects. It was also suggested that endogenously produced (probably platelet-derived) endoperoxides could be redirected into prostacyclin in vivo.

Efficacy and safety of the dipeptidyl peptidase-4 inhibitor sitagliptin compared with α-glucosidase inhibitor in Japanese patients with type 2 diabetes inadequately controlled on sulfonylurea alone (SUCCESS-2): a multicenter, randomized, open-label, non-inferiority trial

We assessed the efficacy and safety of sitagliptin compared with α-glucosidase inhibitor (αGI) in 120 of Japanese patients with type 2 diabetes mellitus (T2DM) inadequately controlled on stable ≤2 mg/day glimepiride alone [mean hemoglobin A1c (HbA1c) 7.7%] by the randomized, active-controlled, non-inferiority trial. Patients were randomly assigned to receive additional sitagliptin or αGI for 24 weeks. The primary endpoint was change in HbA1c from baseline to week 12. After 12 weeks, sitagliptin reduced HbA1c by -0.44% (p < 0.001) relative to αGI. At 24 weeks, the reduction was almost identical between the groups (-0.091%, p = 0.47). Gastrointestinal disorders were more common with αGI than with sitagliptin, but only minor hypoglycaemia occurred in both groups at similar frequency. These data suggested that sitagliptin was not inferior to αGI for reduction of HbA1c in Japanese T2DM patients receiving glimepiride alone, and well tolerated with minimum risk of gastrointestinal symptoms and hypoglycaemia.

Large-scale production and properties of human plasma-derived activated Factor VII concentrate

BACKGROUND AND OBJECTIVES

An activated Factor VII (FVIIa) concentrate, prepared from human plasma on a large scale, has to date not been available for clinical use for haemophiliacs with antibodies against FVIII and FIX. In the present study, we attempted to establish a large-scale manufacturing process to obtain plasma-derived FVIIa concentrate with high recovery and safety, and to characterize its biochemical and biological properties.

MATERIALS AND METHODS

FVII was purified from human cryoprecipitate-poor plasma, by a combination of anion exchange and immunoaffinity chromatography, using Ca2+-dependent anti-FVII monoclonal antibody. To activate FVII, a FVII preparation that was nanofiltered using a Bemberg Microporous Membrane-15 nm was partially converted to FVIIa by autoactivation on an anion-exchange resin. The residual FVII in the FVII and FVIIa mixture was completely activated by further incubating the mixture in the presence of Ca2+ for 18 h at 10 degrees C, without any additional activators. For preparation of the FVIIa concentrate, after dialysis of FVIIa against 20 mm citrate, pH 6.9, containing 13 mm glycine and 240 mm NaCl, the FVIIa preparation was supplemented with 2.5% human albumin (which was first pasteurized at 60 degrees C for 10 h) and lyophilized in vials. To inactivate viruses contaminating the FVIIa concentrate, the lyophilized product was further heated at 65 degrees C for 96 h in a water bath.

RESULTS

Total recovery of FVII from 15 000 l of plasma was approximately 40%, and the FVII preparation was fully converted to FVIIa with trace amounts of degraded products (FVIIabeta and FVIIagamma). The specific activity of the FVIIa was approximately 40 U/ micro g. Furthermore, virus-spiking tests demonstrated that immunoaffinity chromatography, nanofiltration and dry-heating effectively removed and inactivated the spiked viruses in the FVIIa. These results indicated that the FVIIa concentrate had both high specific activity and safety.

CONCLUSIONS

We established a large-scale manufacturing process of human plasma-derived FVIIa concentrate with a high yield, making it possible to provide sufficient FVIIa concentrate for use in haemophiliacs with inhibitory antibodies.

A case of POEMS syndrome with high concentrations of interleukin-6 in pericardial fluid

The POEMS syndrome (plasma cell dyscrasia with polyneuropathy, organomegaly, endocrinopathy of various forms, monoclonal gammopathy, skin changes) is a rare multisystem disorder of unknown pathogenesis. Overexpression of proinflammatory cytokines has been implicated in the pathogenesis of POEMS syndrome, however, it is not known whether there is an association between abnormalities in cytokines and pericardial fluid. We present a case of POEMS syndrome with high concentrations of interleukin-6 (IL-6) in pericardial fluid. In our patient, pericarditis developed into cardiac tamponade, and the concentration of IL-6 in pericardial fluid was remarkably elevated compared with that in serum (1760 vs. 6.57 pg mL(-1)). We suggest that IL-6 is associated with the progression or maintenance of pericarditis as a result of POEMS syndrome.

Diabetic ketoacidosis associated with recurrent pulmonary edema and rhabdomyolysis in a patient with Turner's syndrome

Turner's syndrome is a condition involving total or partial absence of one X chromosome and has been associated with a number of diseases including non insulin dependent diabetes mellitus, abnormalities of glucose metabolism and hypothreosis. There have been many case reports in which Turner's syndrome is associated with type 2 diabetes, but the association with type 1 diabetes and/or life threatening complications is very rare. We present an unusual case of a patient with Turner's syndrome who has type 1 diabetes and is complicated with ketoacidosis, severe acute and recurrent pulmonary edema and rhabdomyolysis.

Fulminant Mycoplasma pneumoniae pneumonia

A 64-year-old woman, who was previously in good health was admitted because of progressive respiratory distress. Her chest radiograph revealed bilateral widespread alveolar infiltrates. She was given a diagnosis of pneumonia caused by Mycoplasma pneumoniae serologically, acute respiratory distress syndrome, and disseminated intravascular coagulation. She died of multiple organ failure despite intensive therapy with mechanical ventilation, intravenous erythromycin and corticosteroids, continuous hemodiafiltration, and plasma exchange. Although Mycoplasma pneumoniae infection is usually a benign self-limited disease, this case emphasizes its potentially serious nature even in normal healthy individuals.

[A case of pseudo-Bartter's syndrome with marked nephrocarcinosis]

A 38-year-old woman was admitted to our hospital on October 21, 1996 for evaluation of thirst, bilateral backache and a feeling of abdominal fullness. She had hypokalemia, normotension, hyperreninemia, hyperaldostronism and hyperplasia of the juxtaglomerular apparatus on renal biopsy. Ultrasonography, intravenous pyelography and computed tomography showed marked bilateral renal calcification. Considering her history of persistent soft stool caused by chronic laxative abuse for 15 to 16 years and past diuretic abuse for several years since 1986, we diagnosed her as pseudo-Bartter's syndrome with nephrocarcinosis. The value of urinary Ca excretion was in the normal range, and acidification disturbance in NH4Cl loading test was revealed. In addition, she had taken analgesics for 2 to 3 years and interstitial nephritis on renal biopsy was seen. It is thus suggested that the cause of nephrocarcinosis in this case was the reduction of Ca solubility in the tubular cavity induced by incomplete renal tubular acidosis associated with analgesic nephropathy or interstitial nephritis caused by hypokalemia.

A case of rheumatoid pericarditis with high concentrations of interleukin-6 in pericardial fluid

A case of rheumatoid pericarditis that developed into cardiac tamponade without deterioration of rheumatoid arthritis is described. The concentration of interleukin-6 (IL-6) in pericardial fluid was notably increased compared with serum. IL-6 may be associated with progression or maintenance of rheumatoid pericarditis.

Growth hormone secreting adenoma with unusual extension: coexisting pituitary cyst and its clinical significance

A 58 year old man showed acromegalic features. The serum growth hormone (GH) level was 7.3 ng/ml and SMC (somatomedin-C) 637 U/ml. Triple stimulation test showed abnormal response compatible with a GH secreting tumour. The conventional enhanced MRI revealed a less enhanced hemisphere-shaped lesion at the right corner of the sella turcica. In addition, dynamic MRI demonstrated an elongated lesion extending to the left beyond the midline. The patient underwent transsphenoidal surgery. Besides the soft and suckable tumour at the right corner, we entered into a small cavity loosely filled with the tumour, which was subsequently also removed. The operative finding corresponded to the lesion shown in dynamic MRI. Postoperative GH and SMC levels became 2.3 ng/ml and 326 U/ml respectively. Incidental pituitary cystic lesions in autopsied cases have been reported to be 6-33%. This case had a GH secreting adenoma with coexisting pituitary cyst. The coexisting pituitary cyst supposedly influenced the unusual shape and extension of the pituitary adenoma. Coexistence of such lesion should be kept in mind for microadenoma on neuroradiological evaluation and on intraoperative inspection surrounding the tumour.

Bilateral pleuritis caused by Legionella micdadei

A 58-year-old woman was hospitalized because of progressive respiratory distress. She had a history of myasthenia gravis and invasive thymoma. After thymectomy, she had been administered oral prednisolone and intrathoracic anti-cancer drugs postoperatively. Her chest radiograph revealed bilateral pleural effusions. Legionella micdadei (L. micdadei) was isolated from the pleural effusions, and she was diagnosed as pleuritis caused by L. micdadei. She died despite intensive therapy with mechanical ventilation, drainage tube in the chest and intravenous erythromycin. Although only two cases of Legionellosis caused by L. micdadei have been reported in Japan, clinicians should be aware of L. micdadei as one of the candidates for infection in immunosuppressed hosts.

Geranylgeranylpyrophosphate plays a key role for the G1 to S transition in vascular smooth muscle cells

Pravastatin, a HMG-CoA reductase inhibitor was found to inhibit DNA synthesis of vascular smooth muscle cells (VSMC) in a dose-dependent manner. Flow cytometric analysis demonstrated that pravastatin induced G1 arrest. Mevalonate restored the inhibitory effect of pravastatin on DNA synthesis and on cell cycle progression, suggesting the importance of mevalonate itself and/or its metabolites in VSMC proliferation. The major intermediate metabolites of mevalonate, geranylgeranyl-pyrophosphate (GGPP), farnesyl pyrophosphate (FPP) and IPP (isopentenyl pyrophosphate) were prepared in the form of liposomes, and the effects of GGPP, FPP and IPP on pravastatin induced inhibition of VSMC proliferation and G1 arrest were examined. Only GGPP restored the pravastatin-induced inhibition of DNA synthesis and G1 arrest. Pravastatin inhibited translocation of Rho small GTPase from cytosol to membrane. By the addition of GGPP, Rho small GTPase are geranylgeranylated and translocated to membranes during G1/S transition. These data suggest that GGPP, rather than FPP or IPP, is an essential metabolite among mevalonic acid metabolites for VSMC proliferation and the G1/S transition.

Eicosapentaenoic acid and docosahexaenoic acid inhibit vascular smooth muscle cell proliferation by inhibiting phosphorylation of Cdk2-cyclinE complex

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the form of triacylglycerol (TG) were dose dependently incorporated into phospholipid fraction of vascular smooth muscle cells (VSMC) and suppressed the proliferation of VSMC. Flow cytometric analysis demonstrated both EPA and DHA inhibited G1/S progression. EPA and DHA inhibited the phosphorylation of Cdk2 protein and Cdk2 kinase activity without altering the amount of cyclin E and p27(kip1) proteins and cyclin dependent kinase activating kinase activity by growth stimulation. This mechanisms remained to be clarified but this is the first report of a novel mechanisms of inhibition of DNA synthesis by EPA and DHA.

Complexes of apoA-1 with phosphatidylcholine suppress dysregulation of arterial tone by oxidized LDL

The aim of this study was to determine whether apolipoprotein A-1 (apoA-1) may suppress the vasomotor dysregulation by oxidized low-density lipoprotein (ox-LDL), which is known to be an atherogenic lipoprotein. The isolated porcine coronary arterial rings and the cultured endothelial cells from the porcine coronary arteries were exposed to ox-LDL in the presence or absence of complexes of apoA-1 with dimyristoylphosphatidylcholine (DMPC/apoA-1), apoA-1 alone, or DMPC alone. DMPC/apoA-1 but not apoA-1 alone or DMPC alone was found to suppress both impairment of endothelium-dependent arterial relaxation and vasocontraction caused by ox-LDL in the isolated porcine coronary arterial rings suspended in organ chambers. DMPC/apoA-1 absorbed lysophosphatidylcholine (LPC) from ox-LDL and decreased the transfer of LPC from ox-LDL to the surface membrane of the cultured endothelial cells, but apoA-1 alone and DMPC alone had no effect. High-density lipoprotein exerted the protective actions mimicking those observed in DMPC/apoA-1. Thus DMPC/apoA-1 decreased the transfer of LPC from ox-LDL to surface membrane by absorbing LPC, leading to the suppression of ox-LDL-induced dysregulation of endothelium-dependent arterial tone. Therefore, apoA-1 appears to require formation of the complexes with phospholipids to prevent the endothelial dysfunction caused by ox-LDL.

Mechanisms of enhanced production of PGI2 in cultured rat vascular smooth muscle cells enriched with eicosapentaenoic acid

The present investigation was performed to clarify the effect of EPA on PGI2 production in vitro using cultured rat vascular smooth muscle cells (VSMC). To simulate in vivo conditions, a triacylglycerol (TG) emulsified form of EPA was used. An increase in EPA content was achieved without alteration of arachidonic acid concentration. These experiments clearly demonstrated that co-incubation of EPA-TG increased PGI2 production by cultured VSMC in a dose dependent fashion. Among polyunsaturated fatty acid TG examined (docosahexaenoic acid, linoleic acid, oleic acid and EPA), only EPA-TG was effective. Cyclooxygenase (COX) was activated, but neither phospholipase A2 nor PGI2 synthase activity was changed. EPA treatment did not alter the amount of COX-1 and COX-2 protein in VSMC. Addition of antioxidants, such as butylated hydroxytoluene or vitamin E, decreased MDA levels in the medium and cells and reversed the enhanced PGI2 production in EPA rich-VSMC. Therefore, the high polyunsaturation of EPA could generate low levels of lipid peroxides and thereby lead to activation of COX and an increased PGI2 production. Although EPA increased PGI2 production, only a negligible amount of PGI3 was produced by rat aortic tissues. Enhanced production of PGI2 might contribute to the anti-atherogenic effect of EPA.

Geranylgeranylated rho small GTPase(s) are essential for the degradation of p27Kip1 and facilitate the progression from G1 to S phase in growth-stimulated rat FRTL-5 cells

Cyclin-dependent kinase (Cdk) enzymes are activated for entry into the S phase of the cell cycle. Elimination of Cdk inhibitor protein p27Kip1 during the G1 to S phase is required for the activation process. An inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase prevents its elimination and leads to G1 arrest. Mevalonate and its metabolite, geranylgeranyl pyrophosphate, but not farnesyl pyrophosphate, restore the inhibitory effect of pravastatin on the degradation of p27 and allow Cdk2 activation. By the addition of geranylgeranyl pyrophosphate, Rho small GTPase(s) are geranylgeranylated and translocated to membranes during G1/S progression. The restoring effect of geranylgeranyl pyrophosphate is abolished with botulinum C3 exoenzyme, which specifically inactivates Rho. These results indicate (i) among mevalonate metabolites, geranylgeranyl pyrophosphate is absolutely required for the elimination of p27 followed by Cdk2 activation; (ii) geranylgeranylated Rho small GTPase(s) promote the degradation of p27 during G1/S transition in FRTL-5 cells.

Characteristics of the pituitary gland in elderly subjects from magnetic resonance images: relationship to pituitary hormone secretion

OBJECTIVE

Physiological changes in the pituitary gland with age have not been fully evaluated. The aim of this study was to clarify the morphological characteristics of the pituitary gland by magnetic resonance imaging(MRI) in elderly subjects and to relate them to pituitary hormone secretion.

DESIGN AND PATIENTS

We investigated the pituitary MRI in 59 elderly (15 males, 44 females; median 82 years) and 41 young (13 males, 28 females; median 34 years) healthy subjects.

RESULTS

Pituitary height, width and volume in the elderly subjects were less than those in the young subjects. Empty sella was more frequently observed in the elderly subjects (19%), especially women, than in the young ones. However, no relation was observed between the pituitary size or volume and basal levels of anterior pituitary hormones. Posterior pituitary bright signal(PBS) on T1-weighted MRI, which is thought to reflect its storage of the neurophysin-peptide complex, was not detected in 29% of the elderly subjects while it could be detected in all the young subjects. None of the elderly subjects showed clinical signs or symptoms of diabetes insipidus. Fasting plasma osmolarity and AVP in the elderly subjects were significantly higher than in the young subjects. Moreover, plasma AVP was significantly higher in the elderly subjects without the PBS than in those with the PBS.

CONCLUSIONS

It is suggested that the excessive release of AVP from the posterior pituitary as a result of persistently raised plasma osmolality in the elderly subjects may lead to depletion of the neurosecretory granules in the posterior pituitary gland and may result in disappearance of the posterior pituitary bright signal on T1-weighted MRI. As these morphological changes might relate to the normal physiological occurrence of ageing, we should be cautious in evaluating MRI of the pituitary gland in elderly subjects.

Quantitative analyses of lesion areas of coronary atherosclerosis in cholesterol-fed rabbits

A simple method to quantitatively evaluate atherosclerosis in the rabbit coronary arteries by measuring macroscopic lesion areas (%) was attempted in the present study. Sixteen rabbits were fed a 0.5% cholesterol diet for 15 weeks and then 9 rabbits were sacrificed whereas the remaining 7 rabbits were maintained for further 9 weeks on a normal chow (at week 24). The left circumflex coronary arteries (LCX) were excised from the rabbit hearts under stereoscopic observation. The prepared arterial strips of LCX were 38.7 +/- 7.1 mm long and all of them reached the cardiac apex from the orifice. At week 15, the lesion area in LCX was negligible (3.2 +/- 0.4%) whereas the aortic lesions significantly developed (50.0 +/- 7.6%). At week 24, atherosclerotic lesions in both LCX and aortas increased to 32.8 +/- 9.2% and 85.9 +/- 5.6%, respectively. This is the first report that determined the luminal surface areas of atherosclerotic lesions in rabbit coronary arteries. This method may be more practical and useful for quantitative evaluation of coronary atherosclerosis in a large number of rabbits than histological observations of serial sections of rabbit hearts.

Lipoprotein(a) induces cell growth in rat peritoneal macrophages through inhibition of transforming growth factor-beta activation

To elucidate the atherogenicity of lipoprotein(a) (Lp(a)), we examined its growth-stimulating activity in rat resident peritoneal macrophages. When macrophages were incubated with Lp(a), cell numbers were increased 1.5-fold as compared with control macrophages. Furthermore, apolipoprotein(a) (apo(a)), a plasminogen-like glycoprotein which is covalently attached to a low density lipoprotein-like particle (Lp(a)), also induced macrophage growth, while the growth-stimulating effect of Lp(a-) was negligible. These results suggest that apo(a) plays an active role in the mitogenic activity of Lp(a). Lp(a)-induced macrophage growth was inhibited by exogenously added active transforming growth factor-beta (TGF-beta) dose-dependently, and also by the addition of plasmin, which converts latent TGF-beta to an active form. Moreover, the amounts of endogenous active TGF-beta in the medium were significantly reduced by the incubation with Lp(a). It is evident from these results that Lp(a) induces macrophage growth by inhibiting TGF-beta activation. The capacity of Lp(a) to stimulate macrophage growth shown here could be novel atherogenic function of Lp(a).

Serum levels of dehydroepiandrosterone sulfate in patients with asymptomatic cortisol producing adrenal adenoma: comparison with adrenal Cushing's syndrome and non-functional adrenal tumor

The reported number of adrenal incidentalomas has been increasing because of wider application of imaging techniques. Patients with asymptomatic cortisol producing adrenal adenoma (ASCA) which secretes cortisol without clinical evidence of Cushing's syndrome has been more frequently observed than previously assumed, and they have a risk of adrenal insufficiency after adrenalectomy. Therefore patients with incidentalomas should be screened for cortisol overproduction. The aim of this study is to discover an easy screening test to uncover ASCA. We investigated the hormone profiles of 4 patients with ASCA in comparison with 11 patients with non-functional adrenal tumor and 10 patients with adrenal Cushing's syndrome. We also investigated the expression of dehydroepiandrosterone sulfotransferase (DHEA-ST) in surgically removed attached non-neoplastic adrenal tissues by immunostaining, which was considered to represent the degree of suppression of the hypothalamo-pituitary-adrenal axis. Serum dehydroepiandrosterone sulfate (DHEA-S) levels of all the patients with ASCA and adrenal Cushing's syndrome were lower than those of healthy subjects of corresponding age, but they were within the normal range in the patients with non-functional adrenal tumors. The serum DHEA-S level reflects the degree of suppression of the normal adrenal gland by cortisol hypersecretion from adrenal tumors. But the serum level of DHEA-S decreases with age, and because the normal range of serum DHEA-S is low in elderly subjects, we should be careful to evaluate the level of DHEA-S in elderly patients with adrenal Cushing's syndrome or ASCA. The immunohistochemical study showed DHEA-ST expression was noticeably suppressed in the adjacent adrenal cortex in ASCA and adrenal Cushing's syndrome. The decreased expression of DHEA-ST may reflect autonomous neoplastic cortisol secretion and subsequent ACTH suppression in ASCA and adrenal Cushing's syndrome. A single measurement of plasma ACTH or measurement of ACTH response to corticotropin-releasing hormone was not enough to screen for ASCA because of the wide variation among the cases. Dexamethasone suppression test is essential in identifying ASCA and also a single determination of serum DHEA-S is easy and may be useful for the screening of ASCA in adrenal incidentalomas in young and middle aged subjects, and is especially useful for outpatients.

Thyrotropin induces G1 cyclin expression and accelerates G1 phase after insulin-like growth factor I stimulation in FRTL-5 cells

We have investigated the mechanism by which TSH pretreatment potentiates insulin-like growth factor I (IGF-I)-induced DNA synthesis in FRTL-5 cells. As previously described, pretreatment with TSH increased IGF-I-induced DNA synthesis, suggesting that the effect of TSH is mediated through the cAMP pathway. TSH and A kinase activators required at least 12 h to precondition cells to respond to IGF-I stimulation. The presence of cycloheximide abolished the effect of TSH to increase IGF-I-induced DNA synthesis. When the time course of thymidine uptake after IGF-I addition was studied, TSH pretreatment increased the maximum DNA incorporation and shortened the G1 phase interval. These results indicated that some proteins induced by TSH are required for the effect of TSH on IGF-I activity, and the proteins are important for cell cycle progression. Cyclins are key regulators of the cell cycle; therefore, we investigated the expression of cyclins D1 and E after TSH stimulation. TSH- and A kinase-activating agents increased the expression of cyclins D1 and E after 24 h. The same amounts of cyclins D1 and E induced by IGF-I were increased after TSH pretreatment. TSH pretreatment induced the expression of G1 cyclin in FRTL-5 cells, and IGF-I caused the accumulation of enough G1 cyclins to drive the cell cycle from G1 to S phase in a short time, which accounts for the effect of TSH on IGF-I induced DNA synthesis.

Eicosapentaenoic acid suppressed the proliferation of vascular smooth muscle cells through modulation of various steps of growth signals

Among fatty acids, only n-3 polyunsaturated fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) inhibited the proliferation of vascular smooth muscle cells. DHA was less effective than EPA. To clarify the anti-proliferative effect of n-3 polyunsaturated fatty acid, we have explored the effect of EPA on the signal transduction pathway of platelet derived growth factor (PDGF). EPA inhibited PDGF binding on its receptor and activation of protein kinase C. EPA also suppressed c-fos mRNA expression, one of immediate early genes, through partly inhibiting c-fos transcription. These data revealed that EPA could inhibit vascular smooth muscle cell proliferation through modulating various steps of the signal transduction by PDGF.

Intravenous injection of rabbit apolipoprotein A-I inhibits the progression of atherosclerosis in cholesterol-fed rabbits

The effects of intravenous injection of purified rabbit apoA-I on the progression of aortic atherosclerosis in cholesterol-fed rabbits were examined. In experiment 1, 28 rabbits were equally divided into groups A and B and fed a 0.5% cholesterol diet for 90 days. For the last 30 days, group B received 40 mg apoA-I every week. The fatty streak lesions in group B (23.9 +/- 15.6%) were significantly suppressed compared with those in group A (46.0 +/- 24.9%) (P < .05). In experiment 2, 33 rabbits were divided into four groups (8 or 9 rabbits per group) and fed a 0.5% cholesterol diet. Group A was killed on day 105, while groups B, C, and D were maintained for an additional 60 days on a normal diet, during which time groups C and D received 1 mg apoA-I every other day or 40 mg apoA-I every week, respectively. The lesions in group C (70.2 +/- 15.4%) and group D (65.7 +/- 20.0%) were significantly suppressed compared with those in group B (86.2 +/- 13.7%) (P < .05) but were not reduced to the level of group A (50.0 +/- 22.9%). Although apparent regression was not observed under these conditions, the present study provided the first evidence for the antiatherogenic effect of homologous and apoA-I on the progression of atherosclerosis in cholesterol-fed rabbits.

Measurement of Lp(a) with a two-step monoclonal competitive sandwich ELISA method

OBJECTIVE

To evaluate the results of Lipoprotein (a)[Lp(a)] measurements by a competitive two-step monoclonal enzyme-linked immuno sorbent assay method comparing them with those by a conventional ELISA.

METHODS

Serum having various isoforms of Lp(a) and purified Lp(a) were assayed using the method described here and commercially available kits. The reference range was determined with the use of 324 normal subjects by means of calculation from Lp(a) results of logarithmic transformation.

RESULTS

Our method takes advantage of a competitive reaction between fixed antibody and free antibody to Lp(a), having the detection range up to 1000 mg/L with the lowest detection limit of 2 mg/L. The anti-Lp(a) monoclonal antibody employed in the assay system reacts uniformly with all phenotypes of Lp(a) but showing very low cross-reactivity for plasminogen and LDL. Within-run and between-run precisions were excellent, giving CVs of 2.9 and 4.0% with mean values of 145 and 635 mg/L, respectively. In comparison of the results by our method with those by a polyclonal method (Biopool) or a monoclonal antibody method (Terumo), they correlated well; Y (our method) = 0.99 x (polyclonal method, Biopool) - 1.9, r = 0.994 (n = 60), and Y = 0.94 X(monoclonal method, Terumo) -9.8, r = 0.97 (n = 60), respectively. The reference range was 105.9 +/- 25.4 mg/L, the difference between the sexes was not significant.

CONCLUSION

Our method has proven highly accurate and specific. It is applicable with auto analyzer because it does not require such a pre-dilution step as is necessary for Lp(a) determination by conventional ELISA assay. Accordingly, we can conclude that our test method is workable for both clinical laboratories and mass screening.

Comparison of monoclonal and polyclonal enzyme-linked immunoabsorbent (ELISA) assays for serum Lp(a) and differences in reactivities to Lp(a) phenotypes

We have prepared a monoclonal antibody to Lipoprotein(a)[Lp(a)] and have used it to develop an ELISA test for assaying Lp(a) in serum. The monoclonal antibody employed in the assay system reacts uniformly with S1, S2, S3 and B phenotypes of isoforms, and no cross-reaction with plasminogen at a concentration of 100 mg/dL was observed. Results of the monoclonal ELISA assay were similar to those obtained with a polyclonal antibody ELISA method and demonstrated a correlation coefficient, r = 0.99 with the equation for the regression line: Y(proposed) = 1.06 x (polyclonal antibody reference ELISA test) = 0.36 (N = 51). Inter- and intra-assay precision(CVs) of the monoclonal ELISA assay were between 2.2-3.6% at a mean Lp(a) concentration range of 19.1-68.2 mg/dL,(N = 12). Assay results of various standards were compared by both monoclonal and polyclonal antibody ELISA tests. We observed some discrepancies between expected concentrations and the polyclonal antibody ELISA assay results, which is thought to be more uniformly reactive to the various Lp(a) phenotypes. The monoclonal antibody employed in our proposed method reacts uniformly with Lp(a) phenotypes, and the assay exhibits excellent sensitivity, specificity, and accuracy and is well suited for clinical use.

[Changes in fatty acid composition, platelet aggregability and RBC function in elderly subjects with administration of low-dose fish oil concentrate and comparison with younger subjects]

Anti-thrombotic and anti-atherogenic effects of eicosapentaenoic acid (EPA) through the modulation of various cell functions related to thrombogenesis have been reported recently. We previously reported that the administration of EPA at low doses could more effectively elevate the plasma EPA concentration in elderly subjects than in younger ones. Magnetic resonance imaging examination of the brain often reveals lacunar lesions in elderly subjects without any signs or symptoms of cerebrovascular diseases. In this study we clarified the effect of administration of low doses of fish oil concentrate on platelet and RBC function in elderly subjects, compared with younger subjects. Thirty six elderly subjects (mean age 78) without any signs or symptoms of cerebrovascular diseases, all receiving the same diet in the same lodging house for the aged, were divided into 3 groups. Different amounts of fish oil concentrate (0.25-0.5 g/day of EPA) were administered to the 3 groups, daily for more than 1 month. Changes of plasma fatty acid composition, platelet aggregability, whole blood viscosity and RBC deformability was examined before and after EPA administration. One month after EPA treatment, the plasma EPA content had increased dose dependently, with suppression of platelet aggregation and improvement of RBC function. In younger subjects receiving the same amount of EPA, the elevation of plasma EPA was less than that observed in the elderly. In summary, low dose EPA administration can improve the function of platelet and RBC to an anti-thrombotic state and would be useful to prevent the occurrence of cerebrovascular diseases in elderly subjects without any side effects.

The capacity of dog lung to release prostaglandin I2 as a biochemical parameter for evaluating lung damage during preservation

The release of prostaglandin I2 (PGI2) from the vasculature is thought to reflect damage to the vessels. Basal and bradykinin (BK)-stimulated release of PGI2 from isolated dog lungs after 6-hr preservation were investigated to evaluate lung damage after preservation. Maximal PGI2 release induced by BK decreased significantly after preservation at 24 degrees C (room temperature), but not after hypothermic preservation at 4 degrees C, although basal PGI2 release without BK stimulation did not change in either group of lungs after preservation. The function of allotransplanted lungs assessed by arterial oxygen tension was impaired by preservation at room temperature but not by hypothermic preservation. No differences were observed by light microscopy in either group in the pulmonary tissues, including the pulmonary artery, after preservation. In summary, damage to the lung after preservation may be reflected by the maximal PGI2 release from the lung after BK infusion. Therefore the maximal PGI2 releasing capacity induced by BK may be a useful biochemical parameter for estimating the viability of preserved lungs.

Eicosapentaenoic acid and docosahexaenoic acid suppress the proliferation of vascular smooth muscle cells

Eicosapentaenoic acid, which is one of the n-3 polyunsaturated fatty acids (PUFA), is reported to exert its antithrombotic and anti-atherogenic effect partly through the modulation of vascular cell functions. Vascular smooth muscle cell (VSMC) proliferation plays an important role in the pathogenesis of atherosclerosis. We reported the differential effect of various PUFA on VSMC proliferation. First we established a method for preparing PUFA rich cells in culture to mimic the in vivo situation using PUFA triacylglycerol emulsion. Using these fatty acid rich cells, we found that only EPA and docosahexaenoic acid, although less potent than EPA, inhibited the proliferation of VSMC among the fatty acids tested. This effect of EPA was reversed by the addition of anti-oxidants. It is suggested that production of the oxidized species at a low concentration from EPA inhibited the proliferation of VSMC. This anti-proliferative effect of EPA and DHA on VSMC could partly explain the anti-atherosclerotic effect of marine lipids.

Malignant exophthalmos associated with multiple myeloma

We report a patient with malignant exophthalmos associated with multiple myeloma which showed no evidence of direct orbital involvement of plasma cells. This exophthalmos had similarities with Graves' ophthalmopathy, but the patient had no detectable autoimmune thyroid diseases. Plasmapheresis was effective not only for the treatment of heart and renal failure due to the myeloma kidney but also for the malignant exophthalmos. As the serum monoclonal IgG level was decreased by plasmapheresis, the improvement of proptosis, visual acuity, and hypertrophy of the extraocular muscle as measured by magnetic resonance imaging were observed. It is suggested that humoral factors removed by plasmapheresis might be involved in the pathogenesis of this nonendocrine exophthalmos.

[Nonfunctioning pituitary tumor--subunit, inactive hormone producing tumor]

Approximately 25-30% of the patients with pituitary adenomas were clinically non-functioning adenoma. Recent studies, using molecular biology techniques combined with culture of removed tumors, have revealed that most of these tumors synthesize glycoprotein hormones and/or their subunits. Recent progress and current diagnostic issues are discussed.

Effect of the infusion of OKY-046, a thromboxane A2 synthase inhibitor, on urinary metabolites of prostacyclin and thromboxane A2 in healthy human subjects

The influence of OKY-046, a selective thromboxane synthase inhibitor, on prostanoid formation in healthy human subjects was studied. Vehicle (5% glucose solution) or OKY-046 in 5% glucose solution at 15 micrograms kg-1 min-1 was intravenously administered to five male healthy volunteers for 6 h. Platelet aggregation and thromboxane B2 (TXB2) formation induced by collagen and arachidonic acid were suppressed by the infusion of OKY-046, while both were not affected by the infusion of vehicle. Urinary excretion of 11-dehydro-thromboxane B2, one of major urinary metabolites of thromboxane A2 (TXA2) was decreased by the infusion of OKY-046, while that of 2,3-dinor-6-keto-prostaglandin F1 alpha, one of major urinary metabolites of prostacyclin (PGI2) was increased. The present study demonstrated that the infusion of OKY-046 improved the balance of TXA2/PGI2 into antithrombotic state in healthy subjects. It was also suggested that endogenously produced (probably platelet-derived) endoperoxides could be redirected into prostacyclin in vivo.

The role of 5-hydroperoxyeicosatetraenoic acid in neutrophil activation

5-Hydroperoxyeicosatetraenoic acid (5HPETE) has been recently reported to play an important role in regulating and modulating neutrophil function. In order to clarify the mechanism of neutrophil activation by 5HPETE, we have measured the cytosolic free calcium, which is thought to be necessary for neutrophil activation using fura-2-loaded human neutrophils. Low concentration of 5HPETE, which is thought to be produced during cell activation, had minimal effect on cytosolic free calcium by itself but dose-dependently augmented FMLP-stimulated increase in cytosolic free calcium in the presence or absence of extracellular calcium without converting to LTB4. 5HPETE had no effect on 3H-FMLP binding to human neutrophils. The present data suggested that 5HPETE would augment FMLP-stimulated increase in cytosolic free calcium by enhancing the influx of extracellular calcium and/or the release of calcium from intracellular pool, which resulted in augmentation of neutrophil activation by primary agonist such as FMLP.

[A case of pre-Cushing's syndrome]

A 66-year-old female was admitted to Chiba University Hospital for the evaluation of a left adrenal mass which was incidentally discovered by computerized tomography. The patient had no clinical signs of Cushing's syndrome. Although the plasma ACTH level was suppressed, serum cortisol and urinary 17-OHCS levels were normal. Serum cortisol was not suppressed by dexamethasone and loss of diurnal rhythm of cortisol was observed. Uptake of 131I-aldosterone in the left adrenal gland was noted, but no accumulation was observed in the right one. Left adrenalectomy was performed. The tumor resected was 20 x 22 x 26 mm in size. Pathological diagnosis was adreno-cortical adenoma. Whether slight abnormality of adrenocortical function without clinical symptoms observed in the present case would develop into a clinically typical Cushing's syndrome remains to be solved.

[Anti-thrombotic and anti-atherogenic action of eicosapentaenoic acid]

Epidemiological studies performed in Greenland Eskimos and Japanese indicated that ingestion of fish meat rich in omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA), reduces the incidence of cerebro- and cardiovascular thrombotic diseases. Therefore, the effect of administration of purified EPA, derived from sardine oil, on hemorrheological properties and serum lipids in patients with thrombotic disorders was studied. Dietary supplementation of EPA resulted in decrease in platelet aggregability with reduction of TXA2 production, prolongation of bleeding time, decrease of platelet adhesiveness, increase of red cell deformability, and improvement of serum lipid concentration. Decrease in platelet TXA2 production may be ascribed to the decrease in arachidonate (AA) content of platelet membrane, inhibition of AA release from platelet membrane and competitive inhibition of AA metabolism at the level of cyclo-oxygenase, by EPA. Administration of EPA increased PGI2 production in the rat thoracic aorta and co-culture of rat aorta smooth muscle cell with EPA also increased PGI2 production, but suppressed smooth muscle cell proliferation. This may be explained by a EPA-derived peroxide stimulation of cyclo-oxygenase activity. Administration of EPA decreased platelet-derived growth factor (PDGF) production in rat peritoneal macrophages. In EPA-rich peritoneal macrophages from rat given EPA, incorporation of acetyl LDL and accumulation of cholesterol in macrophages decreased. This may indicate that dietary supplementation of EPA suppress foam cell formation. An interesting finding is that EPA-rich LDL obtained from rabbits given EPA is less susceptible to Cu(2+)-catalyzed oxidative modification. This seems to indicate that EPA may also suppress lipid peroxidation of lipoprotein.(ABSTRACT TRUNCATED AT 250 WORDS)